Refractory furnace

ABSTRACT

A refractory furnace having an upwardly opening chamber and an overhead cover providing an air curtain seal through a peripheral duct. An inlet leading into the duct registers, when the cover is positioned to close the chamber, with an outlet of a conduit leading from a remote source of pressurized air.

United States Patent Sanderson June 17, 1975 [54] REFRACTORY FURNACE3.623,?!4 ll/l97l Firmin 2 110/173 A 74 [76] inventor: Andrew G.Sanderson, I78 Patton 3'787'l72 m9 Sanderson 432/250 St., King City,Ontario, Canada [22] Filed: Nov. 14, 1973 Primary Examiner.lohn J. Camby[2!] Appl. No.: 415,671

Related US. Application Data [63] Continuation-in-part of Ser. No.346,954, April 2, 7

1973, Pat. No. 3,787,l72. [5 1 ABSTRACT 52 us. c1 432/250; 110/173 A Arefractory furnace having an p y Opening 511 1111. c1. F27d 1/02; F27d1/18 chamber and an Overhead Cover Providing an air [58] Field of Search432/247, 250; 34/242; Iain seal through a Peripheral An inlet leadingM73 R, 173 A into the duct registers, when the cover is positioned toclose the chamber, with an outlet of a conduit leading 5 ReierencesCited from a remote source of pressurized air.

UNITED STATES PATENTS 3,437,326 4/l969 Augustine et al. 432/250 5Claims, 8 Drawing Figures REFRACTORY FURNACE This is a continuationin-part of U. S. Pat. application Ser. No. 346,954, filed Apr. 2, I973,now US. Pat. No. 3,787,172 issued Jan. ll, I974.

The present invention relates to a refractory furnace of the type usinga cover or lid.

In certain large refractory furnaces. such as those used for heatingsteel ingots for rolling, the furnace chamber is closed by a top coveror lid. The refractory material of the cover must be held in a steelframe but the frame cannot rest directly on the walls of the furnacebecause it would deform. For this reason covers have been used whichcarry a downwardly projecting peripheral knife-edge steel rim whichlocates in a longitudinal groove in an upper edge of the walls, thegroove being filled with sand to protect the steel rim from the heat.This construction is unsatisfactory because the sand tends to blow outof the grooves even under slight above-normal air pressure within thefurnace. To meet this problem the steel rim has been replaced in somefurnaces by an air curtain projected downwardly around the rim of thecover from a perforated cover circumscribing the cover. This air curtaincover also has a disadvantage in that, in the battery of furnaces, eachcover must carry its own blower mechanism for supplying pressurized air.In either steel rim covers or air curtain covers the cover itself may bemoved by a travelling crane or on rails external to the furnace and ineither case may be held above the furnace chamber or raised on cornerpillars outside the furnace walls.

It is an object of the present invention to provide a refractoryfurnace, using a cover having an air curtain seal, in which thepressurized air for the curtain is supplied from a remote source.

Example embodiments of the invention are shown in the accompanyingdrawings in which:

FIG. I is a perspective view of the upper portion of a refractoryfurnace with cover;

FIG. 2 is a perspective view, partly broken away, showing one uppercorner of the furnace of FIG. 1;

FIG. 3 is an exploded perspective view of the cooperating pillar andcover fittings for the furnace of FIG. 1;

FIG. 4 is a view in cross-section taken along line 4-4 of FIG. 1;

FIG. 5 is a perspective view of the upper portion of a refractoryfurnace with an alternate embodiment of cover;

FIG. 6 is a perspective view partly broken away showing one upper cornerof the furnace of FIG. 5;

FIG. 7 is a cross-sectional view taken along line 77 of FIG. 6; and

FIG. 8 is a cross-sectional view taken along line 88 of FIG. 6.

The embodiment shown in FIGS. 1 to 4 of the drawings consists ofarefractory furnace 10 comprising a refractory wall 12 enclosing anupwardly opening chamber 14 with a circumscribing, upwardly facing rim16 which is flush with a deck 18. Chamber 14 is closed by a cover 20.

Cover 20 of refractory furnace I0 has a steel frame 22 which carries arefractory lining 24. A pair of parallel beams 26, one at each side offrame 22, are extended at each end to provide bearing means 28. A duct30 circumscribes cover 20 on the underside of the cover facing rim 16 ofrefractory wall 12. Duct 30 is perforated throughout its length toprovide a continuous row of apertures 32 facing rim 16. Each bearingmeans 28 has an inlet duct 34 opening from the underside of the foot andconnecting with duct 30. As seen in FIG. 4 of the drawings, a dividerbaffle 36 is fixed in duct 30 facingduct 34. The underside of eachbearing means 28 carries a foot 38 framing a vertical passage 40 andhaving an inverted trough 42 at its lower end.

Trough 42 of foot 38 is constructed to nest on the upper ridge 44 of apedestal 46 also having a vertical passage 48 which connects withpassage 40 in foot 38. A gasket 50, fixed by bolts 52 to pedestal 46, isinterposed between trough 42 of foot 38 and ridge 44 of the pedestal.

Each pedestal 46 is fixed by bolts 54 to a fixed base such as a pair ofspaced, back-to-back l-beams 56 in deck 18. An air duct 58 leading froma remote source of pressurized air (not shown) branches into lateralducts 60 beneath deck 18 which connect with pedestals 46 and lead intopassages 48 of the pedestals.

In the operation of the embodiment of FIGS. 1 to 4, chamber 14 ofrefractory furnace 10 is charged and cover 20 is moved over the furnaceby suitable means such as a rail carriage straddling the cover. Whencover 20 has been located above furnace 10 it is lowered to have troughs42 of feet 38 nest with ridge 44 of pedestal 46, with gasket 50 betweenthe trough and the ridge. To provide the seal for cover 20, air isforced continuously through duct 58 to pass through each duct 60 andconnected passages 48 and 40 to inlet duct 34 and perforated duct 30where it emerges under pressure from apertures 32 to form an air curtain62 directed against rim 16 of refractory wall 12.

In the alternate embodiment shown in FIGS. 5 to 8 of the drawingsrefractory furnace 10 has a cover closing chamber 14. Cover 70 has asteel frame 72 which carries a refractory lining 74 and a carrying beam76. A duct 78 circumscribes cover 70 and this duct is perforatedthroughout its length to provide a continuous row of apertures 80 facingrim 16 of refractory wall 12. An inlet 81 contains a passage 82 whichleads laterally into duct 80 from an opening defined by a terminal ring84.

An upstanding conduit 86 is located outside refractory wall 12 andterminates at its upper end in an outlet 88 containing a passage 89which leads laterally to an opening defined by a ring 90. Ring 84 isexternally bevelled and ring 90 is internally bevelled to couple withring 84. Ring 90 is mounted on an accordian mount 92. A pair of inlets81 are provided, one located on each of opposed sides of cover 70 whichare parallel to the direction of travel 94 of the cover when closingchamber 14 of furnace 10. Inlets 81 couple with a pair of outlets 88.

In the operation of the embodiment of FIGS. 5 to 8, cover 70 is moved inthe direction of arrows 94 to close chamber 14. As cover 70, approachesthe end of its travel ring 84 meets ring 90 with accordian mount 92absorbing any shock. An air curtain 96 is then provided (see FIG. 8) byintroducing air pressure through duct 86 to duct 78 and downwardlythrough apertures 80 against rim I6. Cover 70 may be moved into aclosing position by any suitable means such as an overhead travellingcrane gripping beam 76 or by rails supporting rollers journalledlaterally on the cover.

I claim:

1. A refractory furnace comprising:

A refractory wall enclosing an upwardly opening chamber;

an overhead cover for the chamber comprising a frame carrying refractorymaterial, a peripheral duct fixed to the frame and having at least oneinlet leading into the duct, and air curtain outlet apertures openingtowards the refractory wall;

conduit means located outside the refractory wall and connectable with aremote source of pressurized air, the conduit means having an outlet;and

the inlet of the cover being constructed and arranged to register withthe outlet of the conduit means when the cover is positioned to closethe chamber 2. A refractory furnace as claimed in claim 1 in which theinlet opens laterally from the duct.

3. A refractory furnace as claimed in claim 2 in which the inlet andoutlet terminate in a pair of elements comprising disengagable couplingmeans.

4. A refractory furnace as claimed in claim 3 in which one of theelements is resilient in the direction of coupling.

5. A refractory furnace as claimed in claim 4 in which the cover isrectangular and the peripheral duct has a pair of inlets one located oneach of those two opposed sides of the cover which are parallel to thedirection of movement of the cover when the chamber is being closed bythe cover.

* i t II!

1. A refractory furnace comprising: A refractory wall enclosing anupwardly opening chamber; an overhead cover for the chamber comprising aframe carrying refractory material, a peripheral duct fixed to the frameand having at least one inlet leading into the duct, and air curtainoutlet apertures opening towards the refractory wall; conduit meanslocated outside the refractory wall and connectable with a remote sourceof pressurized air, the conduit means having an outlet; and the inlet ofthe cover being constructed and arranged to register with the outlet ofthe conduit Means when the cover is positioned to close the chamber. 2.A refractory furnace as claimed in claim 1 in which the inlet openslaterally from the duct.
 3. A refractory furnace as claimed in claim 2in which the inlet and outlet terminate in a pair of elements comprisingdisengagable coupling means.
 4. A refractory furnace as claimed in claim3 in which one of the elements is resilient in the direction ofcoupling.
 5. A refractory furnace as claimed in claim 4 in which thecover is rectangular and the peripheral duct has a pair of inlets onelocated on each of those two opposed sides of the cover which areparallel to the direction of movement of the cover when the chamber isbeing closed by the cover.